Railway-traffic-controlling apparatus



Jun@ 7, 1927, q 1,631,842

H. A. THQMPSON RAILWAY TRAFFIC CONTROLLING APPARATUS Filed Feb. 6, 1924Patented June 7, 1927.

UNITED STATES PATENT OFFICE.

HOWARD A. THOMPSON, OF WILKINSBURG, PENNSYLVANIA, ASSIGNOR TO THE UNIONSWITCH & SIGNAL COMPANY, OF SW'ISSVALE, PENNSYLVANIA, A COR- PORATION OFPENNSYLVANIA.

RAILWAY-TRAFFIC-CONTROLLING APPARATUS,

Application led February 6, 1924. Serial No. 690,929.

My invention relates to railway traffic controlling aiparatus comprisingtrain carried governing means controlled by energy received from thetrackway. More particularly my invention relates to the trackway portionof such apparatus.

I will describe one forni of trackway apparatus embodying my invention,and will then point out the novel features thereof in claims.

The accompanying drawing is a diagrammatic view showing one form oftrackway apparatus embodying my invention.

Referring to this drawing, the reference charzuiters l and l designatethe track rails of a stretch of railway track over which trailicnormally moves in the direction indicated by the arrow. These trackrails are divided, by means of insulated joints 2, into a plurality ofsuccessive track sections of which only one section A-D, is shown in thedrawing.

Section A-D is provided with a track relay R having two windings 7 and9. This relay is so arranged that it will be energized only whenwindings 7 and 9 are supplied simultaneously with alternating currentsof the same frequency but differing in phase. Winding 9 is constantlysupplied with alternating current from some suitable source, such as analternator G, over line Wires 3 and 3a. The relay R is so constructedthat winding 9 has considerable reactance and the current throughwinding 9 therefore lags behind the electromotive force of generator G.The other winding 7 of relay R is con stantly connected with the rails land l adjacent the exit end of section A-D lThis winding 7 has a highimpedance, and for purposes which will appear hereinafter, a resistance8 is interposed between one rail, l, of the section, and winding 7 ofrelay R.

Located at the entrance end of section AMD is a track transformer Thaving its primary winding 5 constantly supplied with alternatingcurrent from line wires 3 and The secondary t of transformer T isconstantly connected with the rails adjacent the entrance end of sectionAMD through a resistance 6. It follows that when section A-D isunoccupied7 alternating current iiows from secondary t of transformer T,through resistance 6, the rails l and laof section A-D, resistance 8 andwinding 7 of relay R in series. Due to the effect of resistances 6 and8, this current is more nearly in phase with the electroinotive force ofgenerator G than is the current through winding t). `Under theseconditions therefore the currents in windings 7 and 9` of relay R aredisplaced in phase and relay lt is energized. The relay R may be used tocontrol traclway signaling means or other traf- .fic governing means inany desired manner, and the current supplied to the section bytransformer T, l will term signaling cnrrent.

Means are also provided for supplying the section with other current forcontrolling the train carried governing means and this current l shalldesignate, for purposes of convenience, train governing current. For supplylng the train governing current to the section I provide atransformer U having its secondary l1 connected with the rails adjacentthe exit end D of the section. Interposed between the secondary 1l oftransformer U and one rail l of the section is a reactive impedance orreactor 10.

The supply of energy to the primary l2 of transformer U is controlled bytratlic conditions in advance of section A-D. For example7 as shown inthe drawing, this control is effected by means of a circuit controller13 operated by a signal S associated with the section to the right ofsection A--D and located at point D. This signal may be of any form andmay be controlled in any suitable manner. Circuit controller 13 isclosed only when signal S indicates proceed7 or caution. Primary 12 oftransformer U is supplied with alternating cur rent from line wires 3and 3a over circuit controller 13. It therefore follows that traingoverning current is supplied to section A-D by transformer U only whensignal S indicates caution or proceed.

The reactor 10 is so proportioned that the current liowing from thesecondary l1 of transformer U through winding 7 of relay R issubstantially in phase with the current in winding 9 of relay R, andtherefore relay R can not be energized by train governing current fromtransformer U. Further pro- `tection may be secured by adjusting theparts so that 'the electromotive force supplied by the transformer U isless than the electromotive force required to be applied Cil acrossrelayvwinding 7 and resistance 8 to cause a sufficiently large currenttoiiow through winding 7 to energize relay R.

It should be pointed out that the track way apparatus here-in shown andydescribed is, suitable forV co-operation with train carried governingmeans in such manner that when kthe train occupies a stretch of. trackwhich` is supplied with alternating current, a proceed indication 1sreceived aboard' the train vand when the train occupies a stretch voftrack towhich no such current 1s supplied,

astop indication is received aboard the train.

In at least one form of train carried apparatus arranged to operate inthis manner the train-carried governing mechanism is controlled by thetrackway current through the medium `of receiving apparatus placed ininductive4 relationwith the track rails in advance of the forward axleof the train. With such apparatus it is obvious that the source of traingoverning current must always be connected with the rails in advance yof the train as otherwise the train governing current would be. shuntedaway from the receiving apparatus by the wheels and axles of the train.

As shownl in the drawing signal S is at proceed, and thereforetransformer Uf is energized. Transformer T is also energized and relay Ris therefore picked up.

I will now assume that a train moving in the direction ofl the arrowenters 'section A`-D; As the train passes point A, signal-A ing currentysupplied by transformer T is shunted away from winding 7 lofrelay, R.Ihaveialread'y explained thattrain governing current from transformer Ucannot pick' up relay R and this relay therefore becomes deenergized.`

As Vthe train proceeds through the section i itis constantly supplied,with train governing current from transformer U, andthe train thereforereceives a proceed indication throughout the section. v y

I ywillnow assume that signal S indicates stop, as when the section tothe right of pointDiis occupiedby a train. The supply ofV energy to theprimary of transformer VUis therefore discontinued. If now a trainproceeds through section A-D, the train will receive a stop indicationthroughoutl I claim is:

l. Railway trafficV controlling apparatus comprising a 'stretchofrailway track, a

track relay having two windings `and arranged to be energized only whenthe currents in said twowindings are displaced in phase and one saidwinding being connectedA with said stretch, means forjconstantlysupplying the remainingwindingof said: relay rio with an alternatingcurrent, meansy for sup-l insulated jointsforming,aneielectrically'isolated section, a sourcerof'alternating trackcircuit current connected across the rails Vad"- jacent4 the entrance`end of said section, means lcontrolled by traffic conditions in ad'-Vvance of said section for connecting a second-'source of alternatingcurrent acrossV the rails adjacent the exit end of said section, and atrack relay connectedacrossthe rails adjacent the exit end lof saidsectionv'and responsive to said track Vcircuit current but not tocurrent froml said second source.

3; In combination, a stretch Vof railway track along which trafficmovesin only `oneV direction, said stretch being provided With insulatedjoints formingA an electrically iso-A lated section, a source ofalternating'track circuit current connected across the rails adjacentthe entrance end off said section, a signal' located at the exit end-0fsaid? sectionA for governing trafiic. in advance ofthe section, meanscontrolled by said-signalnfor connecting asecond source 'of' alternatingcurrent across the railsadjacent the exit end of said section, and atrack relay connected across the rails adjacent the exitfend of saidsection and yresponsive to said track circuit currentbutl not to currentfrom said second surce.V f

4. Railway traffic controlling apparatus comprising a stretchf ofrailway track, a source ofqalternating current connected a.d` jacentone'V end:` of said stretch, a'second source of alternatingcurrent,-rneans responsive to traiiic' conditions for at timessupplyingcurrent from said second source to the' other end of thestretch, and a track relay connected with saidstretch adjacent saidsecond source and responsive to current fromV one only of said sources.

5. Railway traflic controlling apparat-us comprising a stretch ofrailway track, a source of alternating current connected ad- .jacent oneend of said stretch, a-second source of alternating current, meansresponsive to traffic conditions for "at times supplying' current fromsaid second source to the other end ofsaid stretch, and a track relayconnected with said stretch adjacent said second source and responsiveto iurrent from said lirst source but not to current troni said secondsource.

G. In combination, a stretch of railway track provided with insulatedjoints forining` an electrically isolated section, a source ofalternating track circuit current connected across the rails adjacentone end of said section, a signal located adjacent the other end ot saidsection Jfor governing tratu fic out of the section, means controlled bysaid signal for connecting` a Second source oi' alternating 'currentacross the rails adjacent tlie second end of said section, and a trackrelay connected across the rails adja` cent the second end ot saidsection and responsive to said track circuit current but not to currentfrom said second source.

7. Railway tratiic controlling apparatus comprising a stretch of railwaytrack, a track relay having two windings and arranged to be energizedwhen said windings are supplied with alternating` currents or the saineirequency but displaced 1n phase,

ineans it'or constantly supplying one said winding with a irstalternating current, ineans tor constantly connecting the relnainingsaid winding with the stretch, a lirst source of alternating currentconnected with the stretch, nie-ans interposed between said source andsaid stretch ior (,:ausing the current from said source to loe displacedin phase :troni said first current, a second source ot alternatingcurrent connected with the stretch, and nleans interposed between saidsecond source and said stretch it'or causing tlie current troni saidsecond source to loe substantially in phase with said .first current.

In testimony whereof l affix my signature.

HOWARD A. THOMPSON.

